Vertical mixing device for fodder

ABSTRACT

A vertical mixing device for fodder includes a mixing chamber comprising at least two adjacent vertical augers provided in longitudinal direction of the mixing chamber one behind the other at the bottom and between essentially upright walls. Both vertical augers can be driven with the same sense of rotation in order to convey the fodder upwardly. In the wedge areas between the rotational courses of both vertical augers distributor cones are situated at the walls. The surface of each distributor cone comprises guiding surfaces extending with differing steepness from a bottom sided base situated within one wedge area to a tip positioned at least close to the wall. Each distributor cone is inclined obliquely towards one of the vertical augers the sense of rotation of which is directed towards this distributor cone.

[0001] The present invention relates to a vertical mixing device asdisclosed in the preamble part of claim 1.

[0002] In a vertical mixing device as known from practice (distributor:R. M. H.) two verticals augers are provided the distributor cones ofwhich are almost symmetrical because their upper tips are locatedvertically above the centres of the their bases.

[0003] NL 10 06 275 A discloses a vertical mixing device comprising twovertical augers which can be driven with opposite senses of rotation.The vertical mixing device can be filled from the rear side. Both augersrotate with different speeds and are provided with an overlap betweentheir rotation courses. They carry controlled conveying elements. Bothdistributor cones are symmetrical. The upper tip of each distributorcone is situated essentially vertical above the centre of the bases.

[0004] In a vertical mixing device as known from U.S. Pat. No. 5,240,321four vertical augers in total are provided in a series in longitudinaldirection of the mixing chamber. There are partial overlaps between themutual rotational courses of the augers. Said mixing chamber can befilled from one end. The mixed fodder is expelled at the other end.During a mixing procedure the vertical mixing device is elevated at oneof its ends.

[0005] It is conventional to fill the vertical mixing device either fromthe upper side by exterior means or to fill it with fodder by means ofits own filling device situated at the rear end. In case that the mixingchamber is filled from above by exterior means, particularly betweensaid vertical augers, first the fodder is distributed on both verticalaugers. Each vertical auger forms a mound like a mole hill by its upwardconveying effect during the mixing procedure. The distributor conesprovided should prevent dead spaces in which the fodder is accumulatedwithout motion and also should promote a transfer of the fodder from onevertical auger to the next one. Said distributor cones are guiding thefodder from above downwardly and inwardly to the auger lobes. However,the fodder also should move back and forth between both vertical augersin order to avoid irregular feed mixes. If the mixing chamber is filledfrom its rear end it is even more complicated with several verticalaugers to distribute the latest loaded fodder part regularly within themixing chamber. A regular mixture of the fodder hardly can be achievedby the known measures or only after an extremely long mixing duration.

[0006] A distributor cone as mentioned here is to be seen as a structuresimilar to one half of a four sided pyramid separated in a verticaldiagonal plane. Said half pyramid is set with its partition plane to thelongitudinal wall of the mixing chamber. The base sides and the outersurfaces of said pyramid can be concavely curved in upward directionand/or in horizontal direction. The concave curvature in horizontaldirection can be made continuously or can consist of discrete straightsections. The upper tip of the distributor cone can be a true pointedtip or can be designed like a rounded peak.

[0007] It is an object of the invention to create a vertical mixingdevice of the kind as disclosed by which irrespective of the manner offilling the mixing chamber an intensive, regular mixture is achievedafter relatively short mixing duration.

[0008] Said object can be achieved by the features of claim 1.

[0009] By means of the oblique inclination of the distributor conetowards the vertical auger the sense of rotation of which is directedtowards said distributor cone, a significant part of the fodder isconveyed upwardly along the steeper guiding surface of the distributorcone. Said fodder part is then guided over the tip and over the edgeextending towards the tip of the distributor cone to another guidingsurface of the distributor cone and from there to the other verticalauger where it is taken up by said other vertical auger. In a top viewof a well filled mixing chamber a continuous and quick oval circulationof the fodder can been seen which means that from each mound of onevertical auger a significant part of the fodder moves over to the othervertical auger. As a result essentially identical feed mixes areachieved at each vertical auger as well as an intensified regular foddermixing effect within the entire mixing chamber. This is achieved afterrelatively short mixing duration. Contrary to a distributor cone the tipof which is situated almost vertically above the centre of the base andthe guiding surfaces of which are symmetric, the steeper side surface ofthe distributor cone according to the invention is generatingunexpectedly strong rising tendencies for the fodder in co-action withthe circumferential and upward conveying force components of thevertical auger feeding towards said distributor cone said forcecomponent guides considerable fodder parts quickly from one verticalauger over the distributor cone to the other vertical auger. Saidvertical augers may be aligned in the longitudinal direction of themixing chambers, or laterally or even obliquely. In each case it isexpedient to provide distributor cones within the intermediate wedgeareas of the vertical augers.

[0010] The inclination of the distributor cone structurally is achievedby displacing the upper tip, e.g. alongside the wall towards which therespective vertical auger is feeding. By said displacement the guidingsurfaces of the core have mutually different inclinations towards thetip. In relation to the vertical plane the distributor cone is madesignificantly asymmetrical. At the steeper guiding surface the fodderparts arriving from the vertical auger feeding towards said steeperguiding surface climb upwardly until they change over the tip and theupwardly directed edge to the other less steep guiding surface alongwhich they slide downwardly and inwardly to the other vertical augerwhich then coveys the fodder further.

[0011] Expediently the tip of the distributor cone is offset by anextent leading to a geometrical relation according to which the boundarybetween the distributor cone and the longitudinal wall at the sideremote from the auger feeding towards the distributor cone isessentially parallel to a line representing the upward taper of thevertical auger, when looking perpendicularly onto the longitudinal wallof the mixing chamber.

[0012] The guiding surfaces can be formed straight or can extend with aconcave curvature in upward direction to the tip.

[0013] Furthermore, in a horizontal section of the distributor cone, theguiding surfaces may be curved concavely. Said curvature can be auniform curvature or can consist of several straight section.

[0014] From the pointed end of the cone base extending into the wedgebetween the vertical augers an edge extends obliquely upwardly towardsthe sidewardly offset tip. Said edge defines a borderline of the lesssteep descending guiding surface towards the auger conveying the fodderaway. The fodder which already changed over onto said less steep guidingsurface slides down rapidly towards said vertical auger.

[0015] The pointed ends of both wedge areas expediently are located on acentre line extending laterally between the respective two verticalaugers.

[0016] The wall, e.g. a longitudinal wall, at which the distributor coneis located may extend vertically or may be inclined outwardly, dependingon the design of the vertical mixing device. The tip may be situateddirectly at the wall or can be distant from the wall and connected to itby a spacer or the like.

[0017] For easy manufacturing each distributor cone should be aconstruction of welded sheet metal which is prefabricated and securede.g. to the longitudinal wall.

[0018] The tips of the distributor cones provided should be situatedabove the level of the free upper ends of both vertical augers in orderto promote a lively circulation in case of a well filled mixing chamber.The inclined distributor cones are of advantage irrespective of whetherthe mixing chamber is to be filled from one end or by means of exteriormeans from the upper side and between both vertical augers.

[0019] In case of a large volume of the mixing chamber even more thantwo vertical augers may be provided one behind the other. Betweenrespective two vertical augers the oppositely inclined distributor conesare provided. In this way even in a longer mixing chamber a lively ovalcirculation of the fodder is generated alongside the side walls and alsoat the expediently rounded terminal walls. It is to be noted thatadditionally a transfer of fodder also takes place directly between thevertical augers. Said fodder transfer contributes to the regularity ofthe feed mix.

[0020] An embodiment of the invention is explained with the help of thedrawing. In the drawing is:

[0021]FIG. 1 a longitudinal central section of a vertical mixing device,and

[0022]FIG. 2 a top view of the vertical mixing device.

[0023] In the embodiment of FIGS. 1 and 2 a vertical mixing device Mcomprises an oval mixing chamber K which is limited sidewardly byvertical walls 1 a, 1 b and a bottom 2 (walls 1 a, 1 b may be inclinedinwardly or outwardly). At the rear end of mixing chamber K its ownfilling device E1 can be provided and/or at the upper side of mixingchamber K an exterior filling device E2. Within mixing chamber K, e.g.in longitudinal direction one behind the other, two vertical augers V1,V2 are provided, both having auger lobes 3 tapering upwardly to arespective free end 5. Dotted line 4 indicates in the longitudinalsectional view of FIG. 1 the taper of auger lobe 3. Both vertical augersV1, V2 can be driven by not shown drive means in the same sense ofrotation R (in FIG. 2 in clockwise direction) such that they conveyfodder upwardly. The rotational courses of both vertical augers V1, V2close to the bottom are situated close to each other such that betweenboth vertical augers wedge areas are defined which diverge towards walls1 a, 1 b.

[0024] In both wedge areas distributor cones A1, A2 are situated at therespective walls 1 a, 1 b. Each distributor cone A1, A2 includes abottom side base B bounded by concavely curved contours 6, 7intersecting in a pointed region 11 and a straight base longitudinalside 8 at the respective wall 1 a, 1 b. Contours 6, 7 are locatedrelatively close to said rotational courses, i.e., there are passageskept free which should not be too narrow.

[0025] Both pointed regions 11 expediently are situated on a lateralcentre line between the rotational courses of both vertical augers. Atheoretical vertical plane F extending through said pointed regions 11and the centres of the base longitudinal sides 8 serves as a referenceplane for defining the asymmetry of said distributor cones A1, A2. Thetip S of each distributor cone A1, A2 is put offset by a distance X inrelation to said vertical plane F alongside the respective wall 1 a, 1 btowards the respective vertical auger V1 or V2, the sense of rotationalR of which is directed towards the respective distributor cone A1 or A2.In other words the tip S of the respective distributor cone A1 or A2 isshifted in relation to said vertical plane F towards the one of saidvertical augers V1 or V2 which rotates towards said distributor cone.Said distance X is selected such that a contour line 13 of thedistributor cone A1 (in FIG. 1) at the side of tip S remote from thevertical auger V1 is essentially parallel to line 4 representing thetaper of the auger lobe 3.

[0026] A less steep guiding surface 9 extends from said bases contour 6to said tip S. Said guiding surface 9 is limited at one side by wall 1 aor 1 b respectively, and the other side by said edge 12. Another andsteeper guiding surface 10 extends at the other side of edge 12 fromsaid bases contour 7 to tip S. Also said guiding surface 10 is limitedby said wall 1 a or 1 b respectively, and said edge 12. Both guidingsurfaces 9, 10 are e.g. concave.

[0027]FIG. 2 shows in its upper part a wall edge 14 of mixing chamber K,which edge protrudes inwardly from said wall. In this case tip S ofdistributor cone A1 is located with a small distance in front of wall 1a and is connected with wall 1 a by a ridge or spacer such that nofodder is allowed to enter between distributor cone A1 and said wall 1a.

[0028] In a different manner, in FIG. 2, lower part, tip S directly ispositioned at wall 1 b. For clarity reasons wall edge 14 is cut away inthis part of the drawing. Walls 1 a, 1 b e.g. are the longitudinal wallsof mixing chamber K.

[0029] The senses of rotation R of both vertical augers V1, V2 are thesame, i.e. clockwise.

[0030] Operation

[0031] During a mixing operation within the filled mixing chamber K apart of the fodder within the mound covering vertical auger VIincreasingly moves upwardly along the steeper guiding surface 10. Thisis caused by conveying force components of vertical auger V1 in thedirection of its sense of rotation R and also in upward directionco-acting with said sleeper guiding surface 10. This part of the fodderquickly moves over tip S and edge 12 on to the less steeply descendingguiding surface 9 and slides along guiding surface 9 to the othervertical auger V2. Said other vertical auger V2 is taking said part ofthe fodder and works it into its mound. Similarly, a part of the fodderrises along the steeper guiding surface 10 of the other distributor coneA2 due to the feeding effect and the upwardly conveying effect ofvertical auger V2. Also this part of the fodder quickly moves over tip Sand edge 12 onto the less steeply descending guiding surface 9, slidesalong said guiding surface 9 downwardly and towards vertical auger V1where it is taken from vertical auger V1. As a result a circulation ofthe fodder is generated with a circulation direction coinciding with therotational senses R of both augers and alongside the walls. Saidcontinuous circulation leads to regular mixing relationships at bothvertical augers V1, V2 and a rapid mixing effect in the fodder withinmixing chamber K. Other parts of the fodder content also are transferredwithin the wedge areas directly between both vertical augers.

1. Vertical mixing device (M) for fodder, comprising a mixing chamber(K) at the bottom (2) of which between essentially upright walls (1 a, 1b) at least two vertical augers (V1, V2) are provided in longitudinaldirection of said mixing chamber (K), which vertical augers can bedriven with the same sense of rotation for mixing and conveying fodderupwardly, and further including distributor cones (A1, A2) situated atside walls in the wedge areas between the rotational courses of bothvertical augers, each distributor cone having guiding surfaces (9, 10)defining the surface of said distributor cone, said guiding surfaces (9,10) extending from a cone bottom side base (B) located in one of saidwedge areas to an upper tip (S) positioned at least close to said wall(1 a, 1 b), characterised in that each distributor cone (A1, A2) isinclined obliquely to the one of said vertical augers (V1, V2), therotational sense (R) of which at the auger side of said distributor coneis directed towards said distributor cone.
 2. Vertical mixing device asin claim 1, characterised in that said tip (S) of each of saiddistributor cones (A1, A2) is situated offset along said longitudinalwalls with a distance (X) from a vertical plane (F) situated in themidst of both base longitudinal sides (8) of the bases of bothdistributor cones closer to the vertical auger (V1 or V2), therotational sense (R) of which is directed to the auger side of saiddistributor cone.
 3. Vertical mixing device as in claim 2, characterisedin that said tip (S) of said distributor cone (A1, A2) is offset thatfar with respect to said vertical plane (F) that a borderline (13) ofsaid distributor cone at the side of the tip (S) remote from saidvertical plane (F) extends alongside of wall (A1) from said base (B) tosaid tip (S) essentially parallel to a line (4) representing the taperof the auger lobe diameter in upward direction and in a viewperpendicular to both auger axes and in the middle between both verticalaugers.
 4. Vertical mixing device as in claim 1, characterised in thatsaid guiding surfaces (9, 10) extend from said base (B) to said tip (S)either straight or with a concave curvature.
 5. Vertical mixing deviceas in claim 1, characterised in that said guiding surfaces (9, 10) arecurved concavely, seen in a horizontal section of said distributor cone.6. Vertical mixing device as in claim 1, characterised in that seen in ahorizontal section of each of said distributor cones two concave guidingsurfaces (9, 10) form an edge (12) extending from a pointed region (11)of said base (B) upward to said tip (S), said base (B) engaging into awedge area between both vertical augers (V1, V2).
 7. Vertical mixingdevice as in claim 6, characterised in that said pointed regions (11) ofboth bases (B) are located on a lateral centre line between bothvertical augers (V1, V2).
 8. Vertical mixing device as in claim 1,characterised in that each of said inclined distributor cones (A1, A2)is snuggly put against the respective wall (1 a, 1 b), which wall eitheris vertical or is inclined outwardly or inwardly within said mixingchamber (K).
 9. Vertical mixing device as in at least one of thepreceding claims, characterised in that each of said distributor cones(A1, A2) is a welded sheet metal construction.
 10. Vertical mixingdevice as in at least one of the preceding claims, characterised in thatsaid tips (S) of both distributor cones (A1, A2) are situated above thelevel of free upper sides (5) of said vertical augers (V1, V2). 11.Vertical mixing device as in at least one of the preceding claims,characterised in that said vertical mixing device (M) has an own fillingdevice (E1) at least at one longitudinal end of said mixing chamber (K)and/or has an exterior filling device (E2) at a top side of said mixingchamber (K) and between said vertical augers an exterior filling device(E2).
 12. Vertical mixing device as in at least one of the precedingclaims, characterised in that more than two vertical augers (A1, A2) areprovided within said mixing chamber (K), with their auger axes situatedin longitudinal direction of said mixing chamber (K) one behind theother, that between two adjacent vertical augers (V1, V2) at eachlongitudinal wall (1 a, 1 b) a respective distributor cone (A1, A2) isprovided, and that all distributor cones (A1) at said one longitudinalwall (1 a) are inclined in the same direction while the distributorcones (A2) at the opposite longitudinal wall (1 b) all are inclined inthe opposite direction.